Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aminopeptidase (AP) A, B, and M, gamma-glutamyltranspeptidase (GGT), endopeptidase I and II, membrane-associated endopeptidase I and II, dipeptidylaminopeptidase (DAP) I, II, and IV, trypsin and chymotrypsin were investigated with 4-methoxy-2-naphthylamine (MNA) substrates and ester proteinases with n-acetyl-L-methionine-1-naphthylester as substrate in the digestive tract of laboratory rodents. Biochemically, proteinases and ester proteinases show different activities in the salivary glands, esophagus, stomach, liver, pancreas, duodenum jejunum, ileum, and colon; sex differences in proteinase and ester proteinase activity were measured, especially in the submandibular gland of rats and mice. Histochemically these enzymes are preferentially localized in surface membranes, lysosomes, secretion granules, and Golgi apparatus of cells of the endocrine and exocrine secretory system, resorptive system and immune system of the digestive tract. Besides the general occurrence of lysosomal (DAP I and II, single cell types and functional units of these systems possess their own individual proteinase and ester proteinase equipment. The cells of the granulated tubules of rat and mouse submandibular gland contain endopeptidase I and ester proteinases, its acinar cells DAP IV, the chief cells of the stomach APA, enteroendocrine cells APA, APM, and DAP II, hepatocytes DAP IV or GGT and DAP IV, lymphocytes GGT and DAP IV, and enterocytes trypsin, chymotrypsin, and membrane-associated endopeptidase I and II. Sex differences in proteinase activity are most conspicuous in the granulated tubule cells of the rat and mouse submandibular gland. The data suggest that proteinases and ester proteinases are involved in specific functions of the cells of the digestive tract. Furthermore, myoepithelial cells, smooth muscle cells of the muscular layer of the stomach and intestine, connective tissue cells (including mast cells) and fibers, nerve cells of the myenteric plexus and the capillary bed of the digestive organs are equipped with some of these proteinases and with ester proteinases and show organ differences.
 ...
PMID:Investigation of proteinases in the digestive tract using 4-methoxy-2-naphthylamine (MNA) substrates. 701 83

Alcohol can be considered as a nutritional toxin when ingested in excess amounts and leads to skeletal muscle myopathy. We hypothesized that altered protease activities contribute to this phenomenon, and that differential effects on protease activities may occur when: (1) rats at different stages in their development are administered alcohol in vivo; (2) acute ethanol treatment is superimposed on chronic alcohol-feeding in vivo; and (3) muscles are exposed to alcohol and acetaldehyde in vivo and in vitro. In acute studies, rats weighing approximately 0.1 kg (designated immature) or approximately 0.25 kg (designated mature) body weight (BW) were dosed acutely with alcohol (75 mmol/kg BW; intraperitoneal [IP], 2.5 hours prior to killing) or identically treated with 0.15 mol/L NaCl as controls. In chronic studies, rats (approximately 0.1 kg BW) were fed between 1 to 6 weeks, with 35% of dietary energy as ethanol, controls were identically treated with isocaloric glucose. Other studies included administration of cyanamide (aldehyde dehydrogenase inhibitor) in vivo or addition of alcohol and acetaldehyde to muscle preparations in vitro. At the end of the treatments, cytoplasmic (alanyl-, arginyl-, leucyl-, prolyl-, tripeptidyl-aminopeptidase and dipeptidyl aminopeptidase IV), lysosomal (cathepsins B, D, H, and L, dipeptidyl aminopeptidase I and II), proteasomal (chymotrypsin-, trypsin-like, and peptidylglutamyl peptide hydrolase activities) and Ca(2+)-activated (micro- and milli-calpain and calpastatin) activities were assayed. (1) Acute alcohol dosage in mature rats reduced the activities of alanyl-, arginyl- and leucyl aminopeptidase (cytoplasmic), dipeptidyl aminopeptidase II (lysosomal), and the chymotrypsin- and trypsin-like activities (proteosomal). No significant effects were observed in similarly treated immature rats. (2) Alcohol feeding in immature rats did not alter the activities of any of the enzymes assayed at 6 weeks. (3) In immature rats, activities of cathepsins B and D were not overtly affected at either 3, 7, 14, 28, or 42 days. (4) Superimposing acute (2.5 hours) on chronic (4 weeks feeding of immature rats) ethanol treatment (ie, chronic + acute) reduced the activities of cytoplasmic proline aminopeptidase and the chymotrypsin- and trypsin-like activities of the proteasome. (5) Cathepsin D activities were reduced in muscle homogenates upon addition of alcohol and acetaldehyde in vitro. (6) Cyanamide pretreatment in combination with alcohol dosage in immature rats did not significantly alter any protease activities. The data suggests that mature rats are more sensitive to the effects of acute alcohol on muscle proteases. Protease activities may be affected by acetaldehyde or alcohol levels as indicated by in vitro experiments. The reduction in muscle protease activities in chronic + acute alcohol superimposition may reflect the effect of acute alcohol dosage alone. Overall, there was no evidence for increased protease activity in any of the experimental situations.
 ...
PMID:Effect of acute and chronic alcohol treatment and their superimposition on lysosomal, cytoplasmic, and proteosomal protease activities in rat skeletal muscle in vivo. 1178 79